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1
Content available remote Dezodoryzacja powietrza w oczyszczalni ścieków za pomocą otwartego biofiltra
Chmielowiec-Korzeniowska A., Tymczyna L., Bartecki P., Dobrowolska M., Banach M., Drabik A., Pyrz M., Pulit J.
Przemysł Chemiczny
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2015
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T. 94, nr 6
977-981
PL
Zawierające związki siarki powietrze z oczyszczalni ścieków zwilżano do wilgotności 95% w temp. od -2°C do 27°C i filtrowano przez zrębki dębowe, biomasę i pokruszoną korę o temp. 10–21°C. Sprawność dezodoryzacji powietrza wzrastała wraz ze wzrostem temperatury powietrza wlotowego i złoża. Odczyn i wilgotność materiału biofiltracyjnego nie wpływały na skuteczność dezodoryzacji powietrza.
EN
S compds.-contg. air from a wastewater treatment plant was wetted to the humidity of 95% at -2°C to 27°C and filtered through oak chip, biomass and bark beds at 10–21°C. The efficiency of the air deodorization increased with the increasing the inlet air and biofilter temps. Neither pH nor moisture content in the biofilter material showed any effect on the air deodorization efficiency.
2
Content available remote Calibration of the Bodner-Partom Constitutive Model for Vacuum Packed Particles Using Simulated Annealing Algorithm
Zalewski R., Pyrz M., Chodkiewicz P.
Machine Dynamics Research
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2015
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Vol. 39, No. 3
93-101
EN
The work is related to the numerical modeling of Vacuum Packed Particles (VPP)-structures composed of grains enclosed in an elastic envelope and submitted to internal underpressure. The behavior of the material is modeled using viscoplastic law of Bodner-Partom. The inverse problem of constitutive model parameter identification is solved using the non deterministic optimization procedure based on simulated annealing algorithm. The results of numerical simulation are compared with experimental results.
3
Content available Modelling of the Viscoplastic Behaviour of Homogeneous Solid Propellants
Pyrz M., Zalewski R.
Central European Journal of Energetic Materials
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2015
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Vol. 12, no. 1
159--174
EN
This study is concerned with the mechanical properties of homogenous solid propellants. The experimental results demonstrate the high strain rate sensitivity of these materials. A modified viscoplastic model of the Bodner- Partom type was applied to simulate the nonlinear behaviour of solid propellants when subjected to uni-axial loading conditions. The material parameters of the constitutive law were identified numerically using the evolutionary algorithm. The capability of the proposed approach was investigated for a representative solid fuel sample. The efficiency of the method is discussed.
4
Content available Estymacja parametrów modelu tłumika magneto-reologicznego z wykorzystaniem algorytmów genetycznych
Grzesikiewicz W., Makowski M., Pyrz M.
Pomiary Automatyka Kontrola
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2011
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R. 57, nr 9
1044-1047
PL
Praca jest poświęcona opracowaniu metody wyznaczania parametrów modelu tłumika magneto-reologicznego na podstawie badań eksperymentalnych. Obiektem badań był sterowany tłumik magneto-reologiczny (MR), w którym możliwe było sterowanie siłą tłumienia. Do badań numerycznych zaproponowano matematyczny model tłumika MR oraz przedstawiono przykładowe wyniki badań eksperymentalnych i symulacyjnych. Przyjęto kryterium oceny zgodności do oceny przyjętych parametrów modelu na podstawie wyników z badań eksperymentalnych i symulacyjnych. Do estymacji parametrów modelu tłumika MR użyto metody optymalizacyjne, gdzie najlepszą zgodność uzyskano przy metodzie algorytmów genetycznych.
EN
A control algorithm for a damping system equipped with the magneto-rheological damper (MR) is presented in this paper. The magneto-rheological damper (MR) enabling the control of a damping force in time was used as a test object. The paper presents the MR damper mathematical model and some examples of experimental and simulation results. The experimental studies were carried out with use of a hydraulic pulsator and a mechanical system equipped with the examined MR damper. There is described the method for selecting model parameters of the MR damper. To improve simulation and experimental results there was implemented the minimization criterion. The paper discusses several methods of optimized selection of the MR damper parameters. The best results were obtained using the methods based on genetic algorithms. Numerical investigations were performed in Matlab / Simulink with Optimtool Matlab library. Knowledge of the properties of a damper - energy dissipater - and its dissipation characteristics creates the possibility of finding its new applications to vibration control in suspension and transmission system of building structures, machines and machinery.
5
Modelowe badania prototypu tłumika magnetoreologicznego
Bajkowski J., Pyrz M., Zalewski R.
Modelowanie Inżynierskie
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2010
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T. 9, nr 40
7-14
PL
W pracy przedstawiono wyniki badań eksperymentalnych prototypu tłumika magnetoreologicznego, przeznaczonego do wykorzystania w kontrolowanym procesie tłumienia drgań mechanicznych wybranej grupy urządzeń. Główną uwagę skupiono na przedstawieniu zastosowanego rozwiązania konstrukcyjnego oraz na analizie odpowiedzi badanego urządzenia na zadany eksperymentalnie rodzaj wymuszenia kinematycznego. Zgromadzona baza doświadczalna posłużyła, w dalszym etapie, jako punkt wyjściowy do ustalenia reprezentatywnego modelu reologicznego dla rozpatrywanego tłumika. Do analiz numerycznych wybrano model Bouc-Wena. Przeprowadzono estymację parametrów materiałowych modelu, wykorzystując algorytm symulowanego wyżarzania. W końcowej części pracy dokonano weryfikacji dokładności modelu numerycznego poprzez porównanie jego odpowiedzi z rezultatami eksperymentalnymi.
EN
The experimental results of the magnetorheological damper prototype, designed for controlled damping of mechanical vibrations are presented in this work. Main attention is devoted to the description of the considered construction and to the investigation of the damper's response to kinematical excitation applied experimentally. The acquired data was the initial point for the choice of a suitable rheological model for the device under consideration. The Bouc-Wen model has been selected for numerical analysis. The estimation of model parameters was made using the simulated annealing algorithm. At the final part of the paper the exactitude of the numerical model has been verified by comparing it with experimental results.
6
Content available Modeling of Solid Propellants Viscoplastic Behavior Using Evolutionary Algorithms
Zalewski R., Pyrz M., Wolszakiewicz T.
Central European Journal of Energetic Materials
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2010
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Vol. 7, nr 4
289-300
EN
In the paper an initial attempt to the experimental analysis of viscous effects, characteristic for homogeneous solid rocket fuels is proposed. For this reason uniaxial tensile experiments, carried out on dumbbell homogeneous solid propellants have been chosen. Laboratory tests have been carried out on INSTRON tensile testing machine. Research schedule involved destructive tensile tests with various strain rates. Three different values of strain rates have been taken into consideration. Experimentally obtained hardening curves are presented in suitable diagrams. Basing on obtained results, authors confrm the viscoplastic behavior of studied materials. Essential impact of the applied strain rate on the position of experimental hardening curves is observed. Acquired results are the base for the further stage of investigations of homogeneous solid propellants – the modeling of their physical properties. Additionally, numerical modeling of studied phenomena, using the viscoplastic Chaboche’s model, identifed on the basis of experimental data, is presented. The material parameters of the constitutive law are determined numerically using an evolutionary algorithm procedure. The effciency of the model and the identifcation approach are discussed.
7
Content available remote On Updating Finite Element Models of Real Structures Using Genetic Algorithm
Touat N., Pyrz M., Rechak S.
Machine Dynamics Problems
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2008
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Vol. 32, No. 2
74-87
EN
An efficient method of updating numerical models for dynamics problems is presented. The objective is to minimize the difference between measured and simulated vibration data. The corresponding optimization problem is formulated in the modal domain and solved using the genetic algorithm (GA) stochastic algorithm. Original modifications of a standard GA are proposed to improve the updating process efficacy. New versions of GA exploit the speeding up procedures developed in the novel accelerated random search (ARS) algorithm. A finite element model of a lumped mass structure is analyzed to validate the approach. A real beam-like structure model is updated, making use of experimental modal data. The enhanced GA enables us to obtain results well correlated with experiments.
8
Content available remote Modeling of Solid Propellant Non-Linear Properties with Thermal Loading History
Pyrz M., Wolszakiewicz T., Zalewski R.
Machine Dynamics Problems
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2008
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Vol. 32, No. 3
80-90
EN
The paper discusses experimental results obtained for a selected group of solid propellants with and without previous thermal loading history. The viscoplastic constitutive model of Chaboche is proposed to model nonlinear properties of the studied material. An effective method of model parameters identification, based on evolutionary algorithms, is applied. The results of numerical simulations are in very good agreement with experimental data.
9
Content available remote Application of Evolutionary Algorithms to the Identification of Parameters of New Smart Structures : Preliminary Approach
Pyrz M., Zalewski R.
Machine Dynamics Problems
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2006
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Vol. 30, No. 2
136-145
EN
A new "smart structure", based on granular materials encapsulated in an elastic envelope, is proposed and investigated in the paper. Fundamental mechanical properties of the specially prepared granular testing specimens are described by the viscoplastic constitutive Chaboche's model. The experimental results of uniaxial tests are presented and applied to the identification of parameters of the Chaboche's law. The proposed procedure of material parameters estimation is based on evolutionary algorithms, solving corresponding optimization problem. The efficiency of the approach and the quality of the results are discussed.
10
Content available remote Evolutionary programs in the optimization of cementless hip prosthesis
Bauer J., Pyrz M.
Engineering Transactions
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2001
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Vol.49, iss.2/3
417-429
EN
The optimal design of cementless hip prosthesis is investigated in the paper. Design variables are materials (represented by their Young's moduli) of the non-homogenous stem prosthesis, disposed in vertical layers. The minimisation of the interface stress function with constraints on the resorbed bone mass reaction is presented. A simplified two-dimensional FEM model of a stem-bone configuration is considered, enabling however to obtain essential characteristics of the stem-bone load-transfer mechanism. Evolutionary algorithm approach is applied to find the optimal solution.
11
Content available remote Optimization of variable thickness plates by genetic algorithms
Pyrz M.
Engineering Transactions
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1998
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Vol. 46, iss. 1
115-129
EN
The implementation of genetic algorithms to the optimal design of variable thickness plates is presented. Thin, elastic, piecewise constant thickness plates subjected to bending are investigated. The material distribution that minimizes the structural strain energy under constant volume constraint is searched. In numerical examples, square plates loaded by uniform normal pressure are optimized for different boundary conditions. The best designs are compared with the worst solutions, corresponding to the maximization of the strain energy. Significant changes in strain energy can be achieved by modyfying thickness distribution for the same material volume. The performances of the approach are discussed.
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